During the delivery of liquids, such as water, it may be desirable to treat the liquid to create a treated fluid, filter the fluid by passing it through a filtration media, or otherwise condition the fluid before it reaches a user or consumer. For instance, a user may wish to treat water at a point of entry or a point of use to incorporate or remove certain additives. Conventional passive dosing assemblies or filter assemblies may be used to treat or filter the liquid before use. For example, a shower filter may be mounted inline between a shower water inlet and an outlet fluidly coupled to a showerhead.
However, shower filters or other passive dosing assemblies typically are directly coupled to the pressurized water line. When the water line is supplying water, some or all or the flow of water passes through the filter media which may thereby perform its intended purposes of removing certain additives, particles, etc. However, when the flow of water is stopped, air which was compressed in the media chamber may have a tendency to expand, causing water and filter media to be pushed out of the media chamber and into the supply line. Once the system is at rest, the filter media or solute will continue to diffuse out of the media chamber through a high pressure port since the media is moving from a region of high concentration to low concentration. With filter media diffusing out of the media chamber after each shower, dispensing event, or other use, the rated life of the filter is reduced.
Accordingly, a passive system for fluid treatment would be desirable. In particular, it would be desirable to have a passive system for dosing a liquid or filtering a fluid, such as water, flowing through the system without the use of additional active components and while preventing the filter media or solute from flowing back into a supply line when the flow of liquid ceases.